Patent Literatures 1 to 3 disclose technologies for inspecting the presence or absence of attached matter, such as an explosive or narcotic drug, on an inspection object at the boarding gate of an airport or seaport and the like. Patent Literature 4 discloses a technology for preventing the attachment of dust to an object.
In Patent Literatures 1 to 3, it is described that compressed gas is sprayed onto the surface of the inspection object at a wind speed of 20 m/s or more using at least one nozzle, and that the nozzle is moved based on the outer shape of the inspection object by moving joints. It is also described that, using the at least one nozzle for spraying the surface of the inspection object with compressed gas at the wind speed 20 m/s, the compressed gas is also ejected onto an inner wall of a collection unit and/or an arm supporting the nozzle.
The technology proposed by Patent Literature 4 includes a means for ejecting a curtain of air over and along an upper surface a substrate from outside thereof, as the substrate is being transported on a transport belt, and an air suctioning means disposed on the other side, for preventing the attachment of dust and the like onto the substrate using an air flow formed like a curtain over the substrate.